Augmented reality, a field of virtual reality, is implemented by a computer graphic technique that composes a virtual object in a real environment to be shown like an object existing in the original environment.
The augmented reality has a feature of complementing additional information that is difficult to obtain only in the real world by composing virtual objects on the basis of the real world, unlike the existing virtual reality that deals with virtual spaces and objects. That is, a virtual reality technology generally makes users concentrate on the virtual environment, such that the users cannot see the real environment, whereas the augmented reality technology allows users to see the real environment where the real environment and virtual objects are mixed. In other words, the virtual reality shows virtual reality to users instead of the real world, whereas the augmented reality has a difference in that it complements and shows the real world by overlapping virtual objects and the real world to the users, and has a feature of providing the users as a sense of being real, which is better than the virtual reality. For these features, the augmented reality can be applied to various real environments, and particularly, is in the spotlight as the next generation display technology that is suitable for a ubiquitous environment, unlike the existing virtual reality that is restricted only within specific fields, such as a game.
The augmented reality technology can be used for a tabletop system. A table is placed at the center of a room in a home or an office by providing a space for people to hold a discussion or play a game around the table. A tabletop system provides multilateral conference or entertainment, and a multilateral cooperative environment for education and exposition, in consideration of the above.
The earlier tabletop system had users intuitively manipulate two-dimensional information on the table with the user's hands or objects, without using the existing input devices, such as a keyboard and a mouse. A study for receiving various types of inputs by simultaneously recognizing touch of two or more fingers has been conducted; however, there is a defect in that the larger the size of a touch screen, the more the manufacturing cost increases. Meanwhile, an interaction method using physical objects that can be held by hands has been proposed; however, there is a defect in that all of the users cannot acquire the control right to simultaneously interact, because it is dependent on the number of physical objects in a multilateral environment.
Unlike desktops generally equipped with a vertical display device, the tabletop system equipped with a horizontal display device has difficulty in simultaneously showing the same content to users in several directions, because the displayed information or content is positioned slightly to one side. A study for dividing the table screen into a number of users or implementing the table screen in a circular shape so as to be turnable to the left and right, in order to remove the problems have been conducted. The former has a defect in that the larger the number of users, the smaller the divided screen, and the latter has a defect in that users have to compete for the control right to turn the circular screen.
Therefore, it is required to develop a cooperative environment that allows users to share and convert personalized results while interacting with each other, which enables the users to make personalized manipulation through direction control, and at the same time, providing a personalized interface for each user.